Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table ldm_validate_partition_table(): Disk read failed. Dev nbd0: unable to read RDB block 0 nbd0: unable to read partition table INFO: task syz-executor.0:17703 blocked for more than 140 seconds. Not tainted 4.19.125-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29456 17703 6448 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0xe06/0x2eb0 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3aa/0x510 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca69 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fbca66d2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7680 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca784 R15: 00007fbca66d36d4 Showing all locks held in the system: 2 locks held by kworker/u4:1/23: #0: 00000000cefca25c ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x78b/0x1580 kernel/workqueue.c:2126 #1: 00000000f41e8e43 (connector_reaper_work){+.+.}, at: process_one_work+0x7c1/0x1580 kernel/workqueue.c:2130 1 lock held by khungtaskd/1079: #0: 00000000e13b619d (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 4 locks held by systemd-udevd/3699: 1 lock held by in:imklog/6128: #0: 000000009f757023 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by agetty/6354: #0: 0000000013cf72c2 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000044ea241 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.5/9007: #0: 000000006092a75b (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000c1db7b8e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.0/17668: 1 lock held by syz-executor.0/17703: #0: 00000000bc53611c (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.125-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2fe lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3699 Comm: systemd-udevd Not tainted 4.19.125-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:100 Code: 2b 6e 87 4c 89 25 8c 92 06 0a 41 bc f4 ff ff ff e8 0a a4 eb ff 48 c7 05 76 92 06 0a 00 00 00 00 e9 24 ec ff ff 90 48 8b 34 24 <65> 48 8b 04 25 40 ee 01 00 65 8b 15 ec 62 9a 7e 81 e2 00 01 1f 00 RSP: 0018:ffff8880ae7076c0 EFLAGS: 00000293 RAX: 0000000080000102 RBX: 0000000000000001 RCX: ffffffff8597e481 RDX: 0000000000000001 RSI: ffffffff8597e48f RDI: 0000000000000005 RBP: ffff8880a493a180 R08: ffff88808eb96440 R09: ffffed101492744d R10: ffffed101492744c R11: ffff8880a493a267 R12: ffff8880a493a264 R13: ffff8880491ada20 R14: ffff8880491ada18 R15: ffff8880491ada60 FS: 00007f83d4e6e8c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000001d2f5369 CR3: 000000008e2a0000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpumask_test_cpu include/linux/cpumask.h:344 [inline] trace_consume_skb include/trace/events/skb.h:37 [inline] consume_skb+0xaf/0x380 net/core/skbuff.c:704 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1471 [inline] sctp_chunk_put+0x182/0x270 net/sctp/sm_make_chunk.c:1498 sctp_packet_pack net/sctp/output.c:495 [inline] sctp_packet_transmit+0x10c5/0x3360 net/sctp/output.c:609 sctp_outq_flush_transports net/sctp/outqueue.c:1165 [inline] sctp_outq_flush+0x2b2/0x2350 net/sctp/outqueue.c:1213 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1807 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x4d6/0x4ed0 net/sctp/sm_sideeffect.c:1170 sctp_generate_heartbeat_event+0x20e/0x440 net/sctp/sm_sideeffect.c:406 call_timer_fn+0x177/0x700 kernel/time/timer.c:1326 expire_timers+0x24f/0x4f0 kernel/time/timer.c:1363 __run_timers kernel/time/timer.c:1684 [inline] run_timer_softirq+0x218/0x660 kernel/time/timer.c:1697 __do_softirq+0x26c/0x93d kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17b/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:101 Code: 00 00 e9 24 ec ff ff 90 48 8b 34 24 65 48 8b 04 25 40 ee 01 00 65 8b 15 ec 62 9a 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 RSP: 0018:ffff88808eb9f5e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff88808eb96440 RBX: ffffffff8b7ee5a8 RCX: ffffffff835356ad RDX: 0000000000000000 RSI: ffffffff83167d5a RDI: ffff888099ecf000 RBP: ffff888099ecf000 R08: ffff88808eb96440 R09: ffff88808eb9f868 R10: ffffed1011d73f0e R11: ffff88808eb9f877 R12: 0000000000000001 R13: ffff888099022400 R14: 0000000000000486 R15: 000000000000107f strlen include/linux/string.h:270 [inline] symhash+0x1a/0xf0 security/selinux/ss/symtab.c:20 hashtab_search+0x4f/0x230 security/selinux/ss/hashtab.c:88 mls_level_isvalid+0x100/0x1d0 security/selinux/ss/mls.c:168 mls_range_isvalid+0x1c/0x100 security/selinux/ss/mls.c:184 mls_context_isvalid+0x71/0x340 security/selinux/ss/mls.c:200 policydb_context_isvalid+0x31b/0x3d0 security/selinux/ss/policydb.c:992 string_to_context_struct+0x8f2/0xa60 security/selinux/ss/services.c:1438 security_context_to_sid_core.isra.0+0x436/0x560 security/selinux/ss/services.c:1491 security_context_to_sid+0x39/0x50 security/selinux/ss/services.c:1525 selinux_inode_setsecurity+0x197/0x3d0 security/selinux/hooks.c:3501 selinux_inode_notifysecctx+0x2b/0x60 security/selinux/hooks.c:6667 security_inode_notifysecctx+0x6c/0xb0 security/security.c:1343 kernfs_refresh_inode+0x328/0x4b0 fs/kernfs/inode.c:195 kernfs_iop_permission+0x6a/0xb0 fs/kernfs/inode.c:302 do_inode_permission fs/namei.c:386 [inline] inode_permission+0x35c/0x540 fs/namei.c:451 may_lookup fs/namei.c:1703 [inline] link_path_walk.part.0+0x957/0x1220 fs/namei.c:2085 link_path_walk fs/namei.c:2270 [inline] path_lookupat.isra.0+0xe3/0x8c0 fs/namei.c:2318 filename_lookup+0x1b0/0x410 fs/namei.c:2349 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x248/0x7a0 fs/open.c:397 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f83d3ce19c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd29879ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 000055d54e6cdfb0 RCX: 00007f83d3ce19c7 RDX: 00746e657665752f RSI: 0000000000000000 RDI: 00007ffd29879f00 RBP: 00007ffd29879f80 R08: 000000000000c400 R09: 0000000000001010 R10: 00007f83d3f9fb58 R11: 0000000000000246 R12: 000055d54d21a856 R13: 000055d54e6bc440 R14: 00007ffd29879f00 R15: 000055d54e6c82d0